Back to EveryPatent.com
United States Patent | 6,009,170 |
Sako ,   et al. | December 28, 1999 |
A signal transmission method applicable to prevention of modification or alteration of the playback mode information, such as copying management information or charging information. The playback mode information form a terminal 15P is data-converted for ciphering by a playback mode information appendage circuit 14 in a header appendage circuit 13 responsive to the key information from a terminal 15K and the resulting information comprised of the data and the playback mode information is outputted. The reproducing side effects data conversion on the ciphered playback mode information for deciphering, by a playback mode information detection circuit 26 in a header separation circuit 25, using the key information from a terminal 27K, for taking out the original playback mode information at a terminal 27P.
Inventors: | Sako; Yoichiro (Chiba, JP); Osawa; Yoshitomo (Kanagawa, JP); Kurihara; Akira (Tokyo, JP); Kawashima; Isao (Kanagawa, JP); Yoneyama; Shigeyuki (Tokyo, JP) |
Assignee: | Sony Corporation (Tokyo, JP) |
Appl. No.: | 694327 |
Filed: | August 8, 1996 |
Aug 11, 1995[JP] | 7-206351 |
Current U.S. Class: | 380/201; 360/27; 360/60; 705/57 |
Intern'l Class: | G11B 023/28; G11B 015/04; G11B 005/02 |
Field of Search: | 380/3,4,5,10,21,28,22 360/60,27,15 |
5057947 | Oct., 1991 | Shimada | 360/60. |
5185792 | Feb., 1993 | Shimada et al. | 380/4. |
5315448 | May., 1994 | Ryan | 360/60. |
5418853 | May., 1995 | Kanota et al. | 360/60. |
5453968 | Sep., 1995 | Veldhuis et al. | 360/60. |
5570339 | Oct., 1996 | Nagano | 360/60. |
5673357 | Sep., 1997 | Shima | 360/60. |
5689559 | Nov., 1997 | Park | 380/3. |
5719937 | Feb., 1998 | Warren et al. | 380/3. |
5761301 | Jun., 1998 | Oshima et al. | 380/4. |
5799081 | Aug., 1998 | Kim et al. | 380/5. |